This invention relates to a pump apparatus for evacuating containers. The invention is particularly adapted to evacuate air from food storage containers, such as jars and plastic bags.
The prior art is prolific in patents that disclose various types of pumps for evaluating air from food containers. The most pertinent patents to the general subject are believed to be the following:
Gill, U.S. Pat. No. 29,582 PA0 Winters, U.S. Pat. No. 638,383 PA0 Desmond, U.S. Pat. No. 882,874 PA0 Staunton, U.S. Pat. No. 1,601,705 PA0 Herzog, et al., U.S. Pat. No. 2,401,638 PA0 Crook, U.S. Pat. No. 2,648,474 PA0 Haley, U.S. Pat. No. 2,695,741 PA0 Reisinger, U.S. Pat. No. 3,312,256 PA0 Katell, U.S. Pat. No. 3,313,444 PA0 Ruberg, U.S. Pat. No. 4,278,114 PA0 Maruscak, U.S. Pat. No. 4,337,804 PA0 Scanlan, U.S. Pat. No. 4,478,025 PA0 von Bismarck, U.S. Pat. No. 4,575,990 PA0 Hawkins, U.S. Pat. No. 4,583,925 PA0 Bartle, Sr., U.S. Pat. No. 4,745,730 PA0 European Patent No. 0 117 247, 1984 PA0 German Patent No. 33 35 001, 1983 PA0 Swiss Patent No. 200,360, 1939 PA0 U.S. Pat. No. 1,857,015, C. M. Gere PA0 U.S. Pat. No. 1,941,048, W. F. Punte PA0 U.S. Pat. No. 2,214,346, H. E. Pim PA0 U.S. Pat. No. 2,322,236, H. Ingram PA0 U.S. Pat. No. 2,429,984, R. M. Berglund PA0 U.S. Pat. No. 2,772,018, G. Weiss PA0 U.S. Pat. No. 3,313,444, Katell PA0 U.S. Pat. No. 3,581,881, J. C. Hobbs, II PA0 U.S. Pat. No. 4,210,255, Pan PA0 U.S. Pat. No. 4,249,583, Lundbladh
These patents disclose pumps for evacuating either rigid containers(jars) or deformable containers (plastic bags), but not both. Additionally, these arrangements employ complex and difficult to apply check valves to the covers(or lids) of rigid containers to be evacuated.
The pump apparatus in the Schultz, U.S. Pat. No. 4,975,028 issued Dec. 4, 1990, entitled "PUMP APPARATUS FOR EVACUATING CONTAINERS" consists of three principal components; in particular, (1) a specially designed disposable/reusable, pressure-sensitive, adhesive-tape check valve that adheres to a container lid and covers a small air evacuating hole, (2) a reciprocating two-stroke piston pump that features an efficient piston check-valve and a vacuum cup which cooperate with plugable porting to provide for evacuation of both rigid and deformable containers, and (3) an accessory probe which is plugged into a side plugable port of the pump to evacuate deformable containers such as plastic bags, while the bottom plugable port is plugged.
With this pump apparatus, a jar can be reused thousands of times to store anything that will fit and which will keep better in a vacuum. The apparatus also pulls a vacuum on an ordinary plastic zipper-lock type bag and allows the zipper to be closed without losing the vacuum. The apparatus will also evacuate many leak proof bags that might be sealed with a commercial home-style hot-sealing machine.
While the Schultz patented design works well and has achieved considerable commercial success, he devised an improved pumping system that eliminates the need for a check valve in the flexible probe assembly and the requirement for a removable plug to maintain cup suction. The prior in-line check valve has many parts and was difficult to manufacture and expensive to purchase preassembled. The removable plug works well in maintaining suction in the cup but it is easily lost and its use requires careful operator instruction.
In accordance with the invention shown in my U.S. patent application, Ser. No. 018,201, an improved evacuation pump system was provided that is uniquely designed to evacuate both lidded rigid containers and sealable flexible containers with a quick change valve shiftable from one mode to the other without removing or replacing parts.
Toward these ends an elastomeric vacuum cup is shown in that application that also forms one of the end caps for the pump assembly, releasably attached to the lid of a rigid container in the rigid container evacuation mode. This elastomeric cup and end cap, has a cross bore therein that receives a shiftable valve member having an outlet port at one end that releasably connects in one position thereof to a flexible probe utilized in the flexible bag evacuation mode. The valve member is shiftable to a second position where it communicates the interior of the vacuum cup in the rigid container evacuation mode to the pumping chamber and seals the outlet port for the flexible container evacuation probe.
These improvements eliminate the need for the plugs associated with the pumping apparatus described in connection with my U.S. Pat. No. 4,975,028, which not only are easily lost but make the pumping apparatus significantly more difficult to operate, particularly without instructions.
In accordance with the invention shown in my U.S. patent application, U.S. Ser. No. 018,202, an evacuating pumping system was provided that operates in two distinct modes to evacuate flexible containers and rigid containers, and the switch between modes is effected by the insertion or removal of a tethered plug from a single port.
Toward these ends a pump was provided in that application with two inlet ports, one for the flexible evacuation probe and one for the vacuum cup interior. The probe port is selectively closed by a plug that is tethered to the pump to prevent its loss. The pump is provided with a main central inlet passage that connects to both of these inlet ports, the probe port being connected thereto by a transverse passage that intersects the inlet passage, and the suction cup port is a coaxial extension of the inlet passage.
A first check valve is defined by a ball valve and seat in the main inlet passage between the transverse bore and the pumping chamber and operates to block flow to the flexible probe during the discharge stroke of the piston in the flexible bag evacuation mode. A second check valve is defined by another ball and valve seat in the inlet passage but these are positioned between the transverse passage and the vacuum cup. This check valve maintains suction in the cup during the flexible bag evacuation mode which would otherwise be lost in the piston discharge stroke.
Neither of these check valves has any function in the rigid container evacuation mode because they both float in that mode. In that mode the lid mounted valve prevents discharge flow into the container and the removable plug, then in place, prevents flow into the flexible probe port. Since both valves open toward the pumping chamber, neither interfere with rigid container evacuation during the suction stroke.
These two check valves considerably simplify the operation of the pump. When switching from the rigid container mode to the flexible container mode, the plug is removed and the flexible probe inserted in the probe port. The plug cannot be lost because it is tethered to the pump and it is unnecessary to plug the suction cup part as before. Switching back to the rigid container mode is simpler because the user can easily understand without instruction that the flexible probe port needs to be plugged by the plug tethered next to it, and there is of course no need to tell the user to then remove the vacuum cup plug as before because it has been eliminated and its function is achieved automatically by one of the check valves.
There have in the past been provided specially adapted lids for evacuation systems that improve the sealing characteristics over lids originally supplied with the containers by the food processor. The following is a list of patents found in a patentability search particularly related to this subject:
In the Lundbladh, U.S. Pat. No. 4,249,583, a reciprocating pump has a lower rim that is removable from an in situ cover. The cover can be made of plastic and has a short outer rim that surrounds a sealing gasket. The cover stays in place on the container and is essentially flangeless in terms of the lip on the container. Lundbladh states in column 5, "In order to be able to cover containers of widely different dimensions with the same closing cover - - - ". Thus, Lundbladh apparently envisioned using the same cover to accommodate different size containers.
The Katell, U.S. Pat. No. 3,313,444, shows a sealing ring that projects downwardly from a flat cover. Katell does not state that he intends the cover to be utilized with various diameter containers.
While the above prior art is adequate for many purposes, the present invention seeks to provide an improved universal lid for an evacuation system.